Process of making photomechanical printing plates



-April 16, 1929. F. T. POWERS- PROCESS OF MAKING PHOTOMEICHANICAL PRINTING PLATES Filed May 26, 1922 IN V EN TOR Patented Apr. 16, 1929.

UNITED STATES PATENT O'F'FICE FRANK '1. POWERS, OF NEW YORK, N. Y., ASSIGNOR POWERS PHOTO-ENGRAVING COMPANY, A CORPORATION OF NEW YORK.

PROCESS OF MAKING PI-IOTOMECHANIGAL PRINTING PLATES.

Application filed May 26,

The invention relates to making photo-mechanicalprinting plates, and more especlally to a novel method of simplifying and speeding up the making (if such plates.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with. the invention, the same being realized and attained by means of 10 the instrumentalities and combinations pointed out in the appended claim.

The invention resides in the novel and useful step and process herein shown and described. 4

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the princi les of the invention.

Of the rawings:

Fig. 1 is a diagrammatic view and Fig. 2 is a detail of a.spacer.

In certain lines of photo-engraving or photo-mechanical plate making, great speed is tenance of high quality of product. In various branches of the work, as for example the making of plates for daily newspapers, the saving of time, even to the fraction of a minute is very desirable, and usually essential, in order to illustrate the latest news. I At the same time the plates must be of such quality as to produce good results under the well-known exactin and unfavorable conditions of newspaper i lustration.

In other lines of work the saving of time is also very important, for these and other rea-' plant turning out a large volsons. Also, in a ume of work, the saving of even a very small will very substantially increase the output of the plant witha given space, equipment and working force, thereby greatly increasing the step in the making of photo-mechanical plates plate and the requisite and concomitant therewith the mainspacing member 10.

amount of time in the making of each plate- 1922. Serial No. season er or coating of the negative before placing the negative and the sensitized surface of the plate in printing contact relation to impress the image of the negative on the light sensitive surface of the plate. This drying of the negative is a relatively very slow and time consuming operation as it involves the drying of the saturated-image bearing coating, as just explained.

I have invented a very simple process or whereby the time consumed in drying negatives is entirely saved. 's invention consists essentially in providing effectively, in various Ways, a protective interposed dry surface between the light-sensitive surface of the wet negative or the Wet imagebearing layer of the negative, and exposing the plate to the light through the negative while in the printing contact relation.

Thus the time of drying the plate is saved and at the same time the sensitive surface of the plate is preserved from damage or impairment.

In Fig. 1 the negative 1 and the printing plate 5 are shown in printing contact relation but the sensitized surface 6 of the plate and the liquid saturated or impregnated coating 3 of the negative are kept just out of actual contact one with the other by a very thin' This is preferably an open frame just within the edges of the plate and negative, as shown inFigs. 1 and 2. This frame is sufficiently thin that it does not impairthe practical printing contact relation. That is, a sharp plate can be made from the negative without employing parallel light rays.

In all these examples light producing means (shown diagrammatically) maybe provided of any suitable or efficient form for use in 95 making a plate when the latter is in printing I contact relation with the negative.

What I claim is The process of making a photo-mechanical printing plate Which comprises making a -1 negative, and bringing the wet, undried negative and a light-sensitized plate very close together, but not actually touching, the slight separation being effected by placing a very thin spacing frame therebetween.

' In testimony whereof, I have signed my v name to this specificatiom FRANK T. PownRs. 

